Platform API: demoUrl from latestVersion returns broken sandbox preview (GENERATING is not defined)

v0
1

When using the Platform API to retrieve chats via v0.chats.find(), the
latestVersion.demoUrl field returns a vusercontent.net URL that fails to render
with:

ReferenceError: GENERATING is not defined

This affects chats created after the February 2026 sandbox update. Older chats’
demoUrl still render correctly when embedded in an iframe.

Reproduction:

  1. Create a chat via the Platform API (or use a recently created one)
  2. Read latestVersion.demoUrl from the response
  3. Open the URL in a browser or embed it in an iframe
  4. The page is blank with GENERATING is not defined in the console

Expected: The demoUrl should render a working preview of the generated app, as
documented in the SDK examples.

Environment:

  • v0-sdk@0.16.1
  • Embedding via iframe with sandbox=“allow-scripts allow-same-origin
    allow-modals allow-forms allow-popups”

Context: We’re building a tool that lists projects/chats via the Platform API
and embeds their previews. Older demoUrl values work fine — this only affects
chats created after the recent sandbox infrastructure change.

For the same project, the preview works correctly in the V0.dev native UI.

5

Hey! To help debug your v0 project, could you share your v0 chat link?
It looks like https://v0.app/chat/... — you can copy it from your browser’s address bar while in the chat.

You’ll also need to unlist the chat so our team can view it — here’s how: Sharing | v0 Docs

This helps the team reproduce what you’re seeing much faster. Thanks!